Pneumatic door-check.



HJ'ALMER A. NELSON, OF ST. PAUL, MINNE E. WESTERGBEN AND ONE-THIRD TO ERIC MINNESOTA.

SOTA, ASSIGNOR OF ONE-THIRD 'IO GEORGE K L. ANDERSON, BOTH OF ST. PAUL,

PNEUMATIC DOOR-CHECK.

Specification of Letters Patent.

Patented J an. *7, 1919.

Application filed December 15, 1916. Serial No. 137,099.

i To all whom it may concern:

Be it known that I, HJALMER A. NELSON, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented a new and useful Improvement in Pneumatic Door- Checks, of which the following is a specification.

This invention relates to pneumatic door checks and the primary object is a device which is inexpensive and simple in con-- struction and not apt to et out of order.

A further object of this device is to provide a device which has an automatic air release which can be adjusted for different air pressures.

The devices for checking the slam of doors which are now used, are impracticable for general use because of the expensive construction and complicated mechanism, while this device can be applied by any one to the door and door frame.

This device is particularly adapted for use in hospitals, offices and screen and storm doors where it is desired toovercome the noise which is caused by the slamming of the door.

Other features and advantages of this device will be more clearly set forth in the following specification and claims.

In the drawing which forms part of this sp ecification Figure 1 is a front view of this device attached to a door and door frame only a small portion of the door and door frame being shown.

Fig. 2 is a cross section of the device showing it attached to a door and door frame.

Fig. 3 is an alternative form of cylinder used in this device.

Fig. 4 is a bottom view of Fig. 3.

Fig. 5 is a cross section of a detail taken on the line X-X Fig. 2.

In the drawing A represents the cylinder of this pneumatic door check which is secured to the door frame or casing D by means of the screws 1.

A Z shaped arm 13 is adapted to carry the plunger or cylinder C which is secured to the bolt 3 by means of the nuts 4. The bolt 3 is adjustably held on the arm B by means of the nuts 5, so as to adjust the plunger 0 to the desired pos'tion for the different doors. The plunger C is also adjustable on the bolt 3 by means of the nuts 4.

The cylinder A is hollow forming a circular chamber 6 which has an opening 7 on one end, the edges at 8, so as of this opening being beveled to allow the plunger G to freely enter the chamber 6 during the closing of the door E. The other end of the cylinder A is closed and is formed with a flange 9 about the outer edge of the same and in which holes are formed for the screws 1.

The rod tion 10 as 3 is formed with a flattened poris illustrated in Figs. 2 and 5 so as to make it resilient. Thus should the plunger C with the opening the closing of not register or coincide exactly 7 of the cylinder A during the door E, the rod 3 will give sufliciently to allow the plunger C to enter the chamber 6.

The resilient rod 3 thus taking care of any slight change in the position of the door E after the device has been attached and doing away wlth re-adjusting the parts, such as the arm B. It is obvious cylinder A and the the rod 3 could be threaded o inserted a hollow plug 15 is of the passageway pening or chamber 12 in which is coil spring 13 and a ball 14. A threaded in the outer end 12 and is formed with a seat 16 against which the ball 14 is adapted to rest to close the passageway in the plug 15. The spring 13 tends to hold the ball 14 in closed position in the seat 16. An air outlet passageway 17 is formed in the rod 3, thus when the door E is closed and the plunger C enters the chamber 6 of the cylinder A, the air in in the cylinder A will be compressed and when the pressure is great enough to overcome the spring pressure be pressed backward ofi compressed air in through the plug and passageway completely close, plug 15, chamber 13, the ball 14 willthe seat 16 and the the cylinder A will pass 15, chamber or opening 12 17 allowing the door E to but as the opening in the 12 and passageway 17 are small the air passes out slow enough to form an air of the door plug 15 is cushion so as to prevent the slamming E. It will be noted that as the adjustable by screwing it farther 12, the spring pressure against the ball 14 will be increased and by screwlng i t out of the passageway 12, the

front of the plunger C spring pressure will be decreased, thus the valve F in the end of the rod 3 can be adjusted for various air pressures to suit the different occasions for large or small doors.

In applying the pneumatic check to door E and the door frame D, the cylinder A and the arm 13 are secured to the door frame D and door E, respectively sothat the plunger C will coincide perfectly with the opening 7 in the cylinder A and the valve F is set so as to relieve the pressure at the proper time in the cylinder A.

In Figs. 3, an alternative form of cylinder A is illustrated in which the cylinder A is slida'bly secured to the base G so as to allow the use of a stiii or rigid rod 3 in connection with the arm B in place of the resilient rod illustrated in Fig. 2. In this construction, the cylinder A is held on the base G by a screw 18. A circular spring 19 is secured under the head of the screw 18 in an opening 20 formed on the other side of the base G.

The elongated opening 21 formed in the base G allows the cylinder A to slide back and forth in the direction of the opening 21 and the spring 19 holds the cylinder A slidably on the base G but firmly against the same. The sliding of the cylinder A back and forth being designed to do away with any irregularities in the coinciding of the plunger 0 with the cylinder A in closing the door.

In the construction illustrated in Fig. 3, it is not necessary to use the air valve F in the plunger rod 3 as a screw 22 in the passageway 23 which connects with the cylinder chamber 6, is adapted to relieve the air pressure through the passageway 24 which conmeets with the passageway 23. By adjusting the screw 22 to the desired position, the chamber 6 can be connected with the outside atmosphere through the passageways 23 and 24 and the opening between the passageways 23 and 24 can be enlarged or decreased by the adjustment of the screw 22 The plunger or piston C can be made of leather, rubber or any other flexible or sultable material so as to give the desired results. In the use of this device, a separate spring is used on the door to close the same, but it is not illustrated in the drawing.

While the drawingillustrates a particular form and construction of device, I desire to have it understood that I do not wish to confine myself to the exact construction illustrated but desire to protect my invention within the scope of the following claims.

What I claim is:

1. In a device of the class described for pneumatically cushioning a door, a piston adapted to register with a cylinder so as to compress air in said cylinder when said door is being closed, a piston rod connected to said piston and adjustable mezfiis in said piston rod for automatically releasing the compressed air from said cylinder, substantially as described.

2. In a pneumatic door check, comprising, a cylinder which is adapted to be secured to the door frame of a door, a Z shaped holding arm rigidly secured to the door, a piston rod adjustably carried by said arm, said piston rod being formed intermediate its ends with a flat thin flexible portion, a piston adjustably carried by said rod, said piston being adapted to enter said cylinder when said door is being closed and said flexible portion of said piston rod allowing said piston to adjust itself in said cylinder, substantially as described.

HJALMER A. NELSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

